Merchants commonly display their products in shelved structures. In order to provide product et the front of the shelves, the shelves are commonly sloped downwardly so that gravity forces the product to the forward edge of the shelves where it is easily accessible to consumers. The angle of the shelf determines the amount of force gravity will have on the product so that the product moves forward.
Such inclined shelves have been manufactured with tracks or channels parallel to the longitudinally extending portion of the shelves so that the product is displayed in orderly rows. Arranging the products in rows enables the merchant to display different products without products getting mixed up. However, forming channels in the metal shelves is got an economical method of manufacturing the shelves.
A much more economical way of manufacturing shelves having gravity feed channels is to construct a gravity feed track of plastic for insertion inside a flat metal shelf. Many patents disclose a plastic gravity feed track which is inserted into a shelf of a display rack. Each of these track members includes a substantially flat base portion with a plurality of spaced longitudinally extending ribs or runners which project upwardly from the base portion. Channels or grooves are formed between the ribs or runners to receive and hold a product, such as bottled drinks.
The track members are typically of unitary construction, commonly made of extruded or molded plastic. Typical plastics used are high impact polystyrene, polycarbonates, various nylons, or rigid vinyl compositions.
In the case of slip surface members of extruded plastic, the plastic is conventionally impregnated with silicone in order to increase the slipperiness of the plastic so that products may slide more easily down the slip surface member to the front of the dispensing tray. The silicone acts to decrease the coefficient of friction between the slip surface member and the product resting atop the slip surface member. As disclosed in U.S. Pat. Nos. 4,454,949, and 4,416,380, for example, the percentage of silicone typically varies between 0.5 percent (0.5%) and 5 percent (5%).
There have in the past been numerous attempts to reduce the cost of silicone containing low friction slide or slip surface tracks while maintaining a relatively high content of silicone so as to maintain the slipperiness of the track. One such attempt is described in U.S. Pat. No. 4,416,380 which discloses in one embodiment an extruded plastic slip surface including a substantially flat base portion having a series of upstanding ribs. According to the disclosure of the patent, the ribs or runners may be impregnated with about 0.5 percent (0.5%) to 5 percent (5%) silicone to improve slidability and aid in guiding products during their downward movement.
Another U.S. Pat. No. 41565,725, discloses a method of forming a composite track using co-extrusion. According to the disclosure of the patent, high impact polystyrene is extruded simultaneously with a mixture of high impact polystyrene and organopolysiloxane. A thin slide plate made up of a mixture of high impact polystyrene and organopolysiloxane is bonded to a thicker base plane composed of pure high impact polystyrene. Since organopolysiloxane is relatively expensive compared to polystyrene, the resulting co-extruded product is less expensive than a slide plate made completely of a mixture of polystyrene and organopolysiloxane.
While the patents described hereinabove have disclosed techniques for reducing the costs of low friction slide tracks, the resulting tracks are still relatively expensive. Additionally, the tracks described in these patents still are subject to a common problem encountered with all slide tracks. That is, all slide tracks while in use collect dust and dirt and, over time, lose some of their slipperiness and become unattractive as merchandising displays.
It has, therefore, been one objective of this invention to provide a low friction slip surface track which is less expensive to manufacture than prior art tracks, but which is just as effective and slippery as a slide surface.
It has been a further objective of this invention to provide a low friction slip surface track which is more attractive as a merchandising display track than prior tracks and which, in use, hides or disguises dirt collecting in the top surface of the track.
It has been a further objective of this invention to provide a low friction slip surface track composed of an extruded, dark-colored plastic base plate and a plurality of co-extruded ribs or beads of a light color such that the colors correspond to the brand name colors of merchandise displayed atop the tray.